Hadith 3:476

Narrated Abu Said:

Some of the companions of the Prophet went on a journey till they
reached some of the 'Arab tribes (at night). They asked the latter to
treat them as their guests but they refused. The chief of that tribe
was then bitten by a snake (or stung by a scorpion) and they tried
their best to cure him but in vain. Some of them said (to the others),
"Nothing has benefited him, will you go to the people who resided here
at night, it may be that some of them might possess something (as
treatment)," They went to the group of the companions (of the Prophet
) and said, "Our chief has been bitten by a snake (or stung by a
scorpion) and we have tried everything but he has not benefitted. Have
you got anything (useful)?" One of them replied, "Yes, by Allah! I can
recite a Ruqya, but as you have refused to accept us as your guests, I
will not recite the Ruqya for you unless you fix for us some wages for
it." They agrees to pay them a flock of sheep. One of them then went
and recited (Suratul-Fatiha): 'All the praises are for the Lord of the
Worlds' and puffed over the chief who became all right as if he was
released from a chain, and got up and started walking, showing no
signs of sickness.

They paid them what they agreed to pay. Some of them (i.e. the
companions) then suggested to divide their earnings among themselves,
but the one who performed the recitation said, "Do not divide them
till we go to the Prophet and narrate the whole story to him, and wait
for his order." So, they went to Allah's Apostle and narrated the
story. Allah's Apostle asked, "How did you come to know that
Surat-ul-Fatiha was recited as Ruqya?" Then he added, "You have done
the right thing. Divide (what you have earned) and assign a share for
me as well." The Prophet smiled thereupon.